Friction draft-gear.



H. H. WESTINGHOUSE. FRlcTloN DRAFT GEAR. APPLICATION FILED MAR.25, 1907.

Patented Apr.

ITNE-SSES l z @ma to which the draft ing of the car or truck-and for PATENT @Fifllldt HENRY 'HERMAN WESTINGHOUSJE, @E

New nenn, zu. r.'

rnrcrion nears-enen.

Application led March 25, i90?.

,To uit fin/0m it may concern Be it known that l, HENRY H. WESTING- noUsn, a .citizen of the United States, residing at New York, in the county of New j York and State of New York, have invented new and useful Improvements in Friction Draft-Gear, of which the following is a specification. A

This invention relates to yielding resistance mechanism for transmitting stresses between members having a limited relative movement, and is. particularly adapted to be applied as a railway draft and buiiing appliance for transmitting drafty and bufling strains between the draw bar and the frainabsorbing suddenshocks and jars rigging is subjected in the ordinary running and shifting of railway cars.

The object of my present-invention is to vand dissipating the provide improved mechanism having a combined friction and spring resistance which shall be extremely simple in construction, inexpensive to manufacture, and efficient and durable-in its practical operation.

ln the accompanying drawing; Figure 1 is a longitudinal section of a yielding resistance mechanism embodying my improvements; Fig. 2 an end yview of the same; Fig. 3 a sectional view of one end of the apparatus illustrating amodified construction for imparting an initial compression to the main resistancel spring; and Fig. 4 a sectional view of a portion of the apparatus illustrating a modified formoftoggle or cam lever mechanism.

My improvement comprises a combined spring and friction device, in which a preliminary resistance spring is employed for receiving and transmitting the lighter or preliminary stresses and acts on an expanding mechanism to force the friction elements into engagement with each other, and

a main reslstance spring which opposes the v relative movement of the friction elements during the compression of the ments may be conveniently arranged in the form of a casing 3 having frictionv surfaces, and friction strlps, or members,

to slide in said casing and having coperating friction surfaces.

Specication of Letters Patent.

` lentlyv preliminary i spring and then acts in conjunction with the frictional resistance to absorb and transmit 6, adapted Patented nprn ftd, i915.. Serial No. enfilent).

rThe internal friction formed integrally with the casing or .may be formed on detachable wear plates 4 rigidly secured to the casing in any suitable manner, as by means of lugs 5 projecting into openings in saidv casing. ln'this case new wear plates may be substituted for old ones after the latter have become worn.

For the purpose of increasing the area of the contacting surfaces the friction elements may be provided with counterpart longitudinal ribs and grooves which may be wedge-shaped in cross section and slightly tapered, if desired, thereby greatly increasing the frictional resistance exerted between said surfaces.

The main resistance spring l0 bears upon inwardly projecting flanges 9 of the friction strips or members 6, which are also provided with lugs 7 for engaging the ends of plates 4, or other xed portion of the casing, to serve as a stop,`or stops, for holding the members 6 against further outwardmovement.

A preliminaryspring 11 is employed for resisting the lighter stresses and acts upon an expanding mechanism for forcing' the friction elements intoengagement with each other with the desired degree of. pressure.

his mechanism `preferably comprises a toggle device having levers 8 inserted between the bearing plate l2 and the friction members 6, the length and angle of such toggle levers being properly designed to give the desired maximum thrust to the friction members when the preliminary resistance spring is fully compressed.

Another feature of my invention comprises a main resistance spring having a certain amount of initial compression in its normalposition, and this may be convenapplied in any desired manner, as by having a large opening in the end of the casing 3, through which the spring l0 may be inserted and then closed by threaded nut 13, which may be screwed up suficientlyto give the main spring l0 the desired amount of initial compression. By means of this construction the main resistance spring normally exerts a certain constant pressure againstthe friction members 6, holding the same against the stops on the casing and preventing relative sliding movement between the friction elements during the cornpression of the preliminary spring 11.

Another, and perhaps more durable consurfaces may beV struction, for imparting an initial comprespressure of the -preliminary spring undery --become` more or less worn,

vspondingly greater. number v-the bolt 15. The plates 14 may -with central depressed portions,

provement is sion to the main resistance spring, is shown in Fig. 3, in which means, such as plates 14, are employed at opposite ends of the spring 10 and connected by bolt 15 and nuts 16. In this construction the lugs and stops of the Fig. 1 structure may be dispensed with as the spring is prevented from expanding beyond the point to which it is adjusted by be formed to provide recesses for the connecting bolt and nuts during the compression of the main resistance spring.

According to the modication schown in '"Fig. 4,' the toggle levers are made in the form of cam levers 8', which have cam surfaces bearin upon each other and upon the plate 12 of the preliminary spring .11. With' this construction of levers, the cam surfaces may be properly designed to compensate-for the wear of the friction ele-l ments, so that the lateral thrust, due to the maximum compression, will remain substantially constant, even when the friction plates and thereby secure the desired maximum amount of frictional resistance throughout the life of the ear. i

While the dr-awingshows the casing as of, and containing only twov toward thel other, as is well understoodby all familiar with the art. Inn the normal position' of the parts the friction members 6 project outward beyond the endof the casing, and the preliminary spring 11 extends beyond the ends of the toward.`the other under a as shown',

the outer end of the` sprinl friction members, s o that, as one of the follower plates of the rigging begins to move stress, the preliminary spring 11 is the first to be compressed. Under the stress imparted to it lduring preliminary compression the spring 11 acts through the 4toggle lever mechanism tol expand the friction members and force the frictional surfaces into engagement with thev desired pressure, but

there will be no sliding movement of the friction members Within the casing, as the` has suicient force, l

main resistance spring due to its initial compression, tohold friction members against the stops and prevent preliminary spring has such action until the been fully compressed and the follower plates bear 'against the outer ends of the friction strips 6. parts under greater stresses then operate to compress the main resistance spring 10, so that the combined force of the main spring and the frictional resistance between the elements is exerted in opposition to these stresses, thereby giving a hlgh maximum capacity to the mechanism.

-Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

In a yielding resistance mechanism, the combination with a casing having friction surfaces, friction members in said casing, andan expanding device for the friction members, of a preliminary resistance spring acting on said expanding device, stops for limiting the movement o the friction members in one direction, spring free to expand against the friction members to thereby exert a pressure tending to hold the friction members, against said stops, and an adjustable nut bearin against and a apted to be screwed up to place e spring under initial compression.

In testimony whereof my hand.

I have hereunto set HENRY HERMAN WESTINGHOUSE. l Witnesses:

R.. F. EMERY, J. B. MACDONALD.-

draft or buiiing a main resistance 

